Security options for avoiding on-chip safety guide

Security options
Vehicle security relies significantly on the electronics of the automotive system. Hence it is extremely important to safeguard the electronic system and data stored in it. Below are a few options for securing the vehicular system. A system can be locked to avoid manipulation of configuration data that would disrupt the proper functioning of the chip. A password mechanism can be deployed to unlock and enable reconfiguration. This is a simple and cost-effective single-tier security measure.

Redundant critical on-chip modules like processor, ISO, DMA controller, internal clock generator, and communications peripherals can improve reliability should a primary hardware module become non-functional while the vehicle is running. Such a system can have in-built error detection mechanisms and on-the-fly switching to redundant hardware to mitigate threats to passenger safety.
But this kind of redundant hardware architecture comes with the penalty of increased area and higher power management in silicon. Area penalties can be minimized by intelligent selection of which functions need to be duplicated in silicon. Power can be minimized by adopting power and clock gating in the redundant modules. Some  in-vehicle computers can be implemented in lock-step of each other, where primary and redundant modules process the same input. Mismatch in the output of the lock-step modules indicates a defect in either of the modules. The system can switch itself off or take appropriate safety measures to avoid any real-time failure. Redundant hardware should be placed quite far in silicon from the primary embedded systems to avoid tampering of both modules together.

refer to: http://www.edn.com/design/automotive/4421704/Safety---security-architecture-for-automotive-ICs